React – “‘value’ prop on ‘input’ should not be null” for some input but not others

Thanks to @ShubhamKhatri and @Dekel for pointing me in the right direction on this – I hadn’t even considered the fact that the empty string set in the constructor was being overwritten with a problematic value. It turns out that the source of the issue was that after setting the value of description as an empty string, my API was overwriting it with null.

I resolved this by tweaking my render method like so:

let groupDescription;

if (!this.state.group.description) {
    groupDescription = ""
} else {
    groupDescription = this.state.group.description
}

return (
    <label>Description<br />
        <input
            type="text"
            name="description"
            value={groupDescription}
            onChange={this.handleChange}
            maxLength="99" />
    </label>
)